Site Description Bethania Welsh Baptist Chapel was originally built in 1832 by builder Mr Hurley of Maesteg. It was rebuilt in 1840-1, probably enlarged in 1859 and rebuilt again in 1898. In 1908 a new chapel was built on the same site to the designs of architect William Beddoe Rees. Rees's design is in the Classical Beaux Arts style with a gable-entry plan. The façade is of three bays, each defined by pilasters topped by a decorative shield. The wide central bay has an entrance flanked by large oculi with quarter-keyed dressings. Above, a large, rectangular 80-pane window is flanked on each side by an Ionic column and a smaller 32-pane window. The side bays have entrances with above, 32-pane windows set in surrounds with exaggerated semi-circular pediments. The central bay is gabled with a semi-circular light resting on the entablature which reads `CAPEL Y BEDYDDWYR 1908 NEILLDUOL'. The side bays have shouldered pediments and the whole façade is finished off by urns above the pilasters and a carved stone set at the peak of the gable. The side bay detail returns for the first bay on the side elevation, the remainder consisting of two tiers of plain windows.

The interior has seats for 1001. An entrance lobby is separated from the main chapel by a screen with stained glass panels. At either side this gives access to open stair wells to the gallery. In the main body of the chapel, a gallery runs round all four sides, the rear side being largely taken up by the organ, which partly set into a round-arched recess. The gallery is carried upon cast-iron columns which, at the sides, continue to an arcade of six delicate round arches reminiscent of Richard Owens' Capel Seion, Aberystwyth. The front of the gallery is of cast-iron with decorative panels of palmettes. The pulpit is set in front of the organ gallery and is a raised rostrum type with a projecting central section carried on a sigle pedestal, and is accessed by stairs either side. The Sedd Fawr in front, is bounded by railings with cast-iron panels similar to those of the gallery, the front railing being in a convex curve. The pews are of the plain bench type and on the ground floor and are divided into three blocks by the twin aisles, and are curved to match the Sedd Fawr. The middle block has staggered central dividers. In the gallery the pews are curved round the corners but are otherwise straight.

Bethania is now Grade II Listed as one of the best surviving architectural achievements by a major chapel architect in his powerful Beaux Arts style.